Department of Animal Science, Michigan State University, East Lansing 48824.
Department of Animal Science, Michigan State University, East Lansing 48824.
J Dairy Sci. 2019 Sep;102(9):8120-8126. doi: 10.3168/jds.2019-16307. Epub 2019 Jun 20.
The objective of this study was to determine the effects of 2 amounts of propionic acid (PA) infused intraruminally at 2 rates of infusion at the initiation of meals on the feeding behavior of Holstein cows in the postpartum period. We hypothesized that the amount and length of time of infusions would interact to affect feeding behavior: rapid infusion of a higher dose of PA would result in larger meal size with greater time between meals compared with a slower rate, whereas faster infusion of a lower dose of PA would reduce meal size and the time between meals compared with a slower infusion of the same dose. Eight ruminally cannulated, multiparous Holstein cows were used in a 4 × 4 Latin square design experiment. Cows were blocked by parturition date and randomly assigned to treatment sequence within square. Treatments were infusion of 2.5 L of 0.5 M (HI) or 0.2 M (LO) solutions of PA at initiation of meals over 5 min (FST) or 15 min (SLW) for 12 h following feed delivery. Contrary to our hypothesis, no interaction between amount and rate of infusion was detected for any feeding behavior parameter measured. The FST treatments did not affect dry matter intake or metabolizable energy intake compared with SLW. The FST treatments tended to increase meal length compared with SLW (28.1 vs. 22.7) but did not affect meal size. The FST treatments tended to decrease total eating time (108 vs. 122 min/12 h) but did not affect meal frequency compared with SLW. The HI treatments decreased dry matter intake (7.4 vs. 11.5 kg/12 h) and total metabolizable energy intake (22.5 vs. 29.1 Mcal/12 h) compared with LO by decreasing meal frequency (5.8 vs. 7.5 meals/12 h). The HI treatments decreased eating time (103 vs. 127 min/12 h) compared with LO but did not affect meal size. Further research is warranted on the effects of the temporal supply of propionate on propionate metabolism and feeding behavior.
本研究旨在确定在进食开始时以 2 种速度经瘤胃内输注 2 种剂量丙酸对产后荷斯坦奶牛采食行为的影响。我们假设输注量和输注时间会相互作用影响采食行为：与较慢的输注速度相比，快速输注较高剂量的 PA 会导致更大的采食次数和采食之间的时间间隔；而与较慢的输注速度相比，快速输注较低剂量的 PA 会减少采食次数和采食之间的时间间隔。8 头经瘤胃内置管、经产的荷斯坦奶牛采用 4×4 拉丁方设计实验。根据产犊日期将奶牛分为若干组，并在每个方内随机分配到处理顺序。处理是在给料后 12 h 内，于采食开始时经瘤胃内输注 2.5 L 0.5 M（HI）或 0.2 M（LO）的丙酸溶液，输注速度分别为 5 min（FST）或 15 min（SLW）。与我们的假设相反，在测量的任何采食行为参数上，输注量和速度之间没有检测到相互作用。与 SLW 相比，FST 处理并没有影响干物质采食量或可代谢能采食量。与 SLW 相比，FST 处理增加了采食时间（28.1 比 22.7），但没有影响采食次数。FST 处理有减少总的采食时间（108 比 122 min/12 h）的趋势，但与 SLW 相比，没有影响采食频率。HI 处理通过减少采食次数（5.8 比 7.5 次/12 h），降低了干物质采食量（7.4 比 11.5 kg/12 h）和总可代谢能采食量（22.5 比 29.1 Mcal/12 h）。与 LO 相比，HI 处理减少了采食时间（103 比 127 min/12 h），但没有影响采食次数。需要进一步研究丙酸的时间供应对丙酸代谢和采食行为的影响。
